Row data from a comma-delimited field used within a select query - sql-server

Question

I am trying to build a single select query that returns
a list of Product Type Description using Table1 that is not
in the ExcludedList of Table2.
I have the following tables and data in SQL Server 2008.
Table1(nProdType INT, sProdDesc VARCHAR)
nProdType SProdDesc
----------- --------------------
1 Pencils
2 Paper
3 Pens
4 Markers
5 Erasers
6 Crayons
7 HighLighters
8 Rulers
Table2(ClassID INT, ExcludeList VARCHAR)
ClassID ExcludedList
----------- --------------------
100 2,3,4,8
101 1,2,5,6,7,8
102 4,5,6,7
103 1,2,3,4,5,6,7,8
104 7
The query should return the following:
ClassID nProdType sProdDesc
-------- --------- --------------
100 1 Pencils
100 5 Erasers
100 6 Crayons
100 7 HighLighters
101 3 Pens
101 4 Markers
102 1 Pencils
102 2 Paper
102 3 Pens
102 8 Rulers
..and so on..
I know how to build (and of course there are plenty solutions in SO) a function to split the comma-delimited field but they return ALL the rows in the table and I want it to be per record (ClassID) so that I can query to see what's not in the ExcludedList. I am trying to not code this in C# or to use a RecordSet.

Answer 1

You can use a CSV Splitter for this. Here is the DelimitedSplit8K function by Jeff Moden.
;WITH CteDelimitted AS(
SELECT
t.ClassID,
nProdType = CAST(s.Item AS INT)
FROM Table2 t
CROSS APPLY dbo.DelimitedSplit8K(t.ExcludedList, ',') s
),
CteCross AS(
SELECT
t2.ClassID,
t1.nProdType,
t1.SprodDesc
FROM Table1 t1
CROSS JOIN(
SELECT DISTINCT ClassID FROM Table2
)t2
)
SELECT *
FROM CteCross c
WHERE NOT EXISTS(
SELECT 1
FROM CteDelimitted
WHERE
ClassID = c.ClassID
AND nProdType = c.nProdType
)
ORDER BY ClassID, nProdType
SQL Fiddle
Another approach using NOT IN:
WITH Cte AS(
SELECT
t2.ClassID,
t1.nProdType,
t1.SprodDesc
FROM Table1 t1
CROSS JOIN(
SELECT DISTINCT ClassID FROM Table2
)t2
)
SELECT *
FROM Cte c
WHERE c.nProdType NOT IN(
SELECT CAST(s.Item AS INT)
FROM Table2
CROSS APPLY dbo.DelimitedSplit8K(ExcludedList, ',') s
WHERE ClassID = c.ClassID
)
ORDER BY ClassID, nProdType
SQL Fiddle